SQL比较，其中在表2中找不到表1的值，并将结果显示为表3

Question

I was trying someting like:

Select Items 
From Table1 
Where Not Exists (
    Select Items 
    From Table2 
    Where Table2.Items = Table1.Items) As Table3.Items

but somehow not working so can anywone tell me how can i achive this?

Answer 1

If you want to create a new table with this results, you can try this:

Select Items 
Into Table3
From Table1 
Where Not Exists (Select Items From Table2 Where Table2.Items = Table1.Items) 

Answer 2

If you're looking for rows in t3 that do exist in t1 but not in t2 , try:

select  t3.Items 
from    table3 t3
where   exists
        (
        select  *
        from    table1 t1
        where   t1.Items = t3.items
        )
        and not exists
        (
        select  *
        from    table2 t2
        where   t2.Items = t3.items
        )

Answer 3

Another solution is except :

select *
from
(
    Select Items 
    From Table1
    except
    Select Items 
    From Table2
) as Table3